With the advancement in scientific technologies and the modularization and miniaturization of camera lens, it is now possible to produce digital cameras having a very small volume, and most of currently available mobile phones are provided with the function of a digital camera. On the other hand, to highlight the differences between the advanced camera devices and the low-level camera devices, higher image quality and more functions, such as highly increased pixels, multi-point auto-focus (AF) function, anti-shake (AS) function, etc., have been further added to the advanced camera devices.
However, every new function added to the image capturing module of a camera device would necessitate the increase of a corresponding modular mechanism to thereby increase the volume of the image capturing module. Therefore, it has become a target of all image capturing module manufacturers to further reduce the volume of the capturing module that has more functions.
There are various types of auto-focus driving structures for the conventional miniature lens. Among others, the voice coil motor (VCM) is the currently most widely employed auto-focus driving structure. The VCM includes an assembly of windings, magnets and plate springs to hold a lens thereto, so that the lens is able to move forward and rearward in an optical axis direction to thereby achieve the object of auto focusing or zooming. The VCM has the advantages of small volume, low power consumption, accurately actuated displacement, and cost-effective, and is therefore very suitable for short-distance driving in miniature lens auto-focusing.
With respect to the anti-shake function, it is achieved mainly through several ways. For example, the imaging element can utilize a compensation movement of a mechanism supporting frame to offset the influence of shake during shooting picture on the forming of a blurred image. Or, the lens can be provided with a mechanical structure to eliminate the shake. Or, two gyro sensors can be used to detect any vibration of the imaging element in horizontal and vertical directions, and use push by magnetic force to compensate such vibration.
Japanese Patent Laid Open No. 2002-207148 discloses a camera device as shown in FIG. 1, in which flexible sections 400-403 made of metal wires are used to hold a circuit board 301 of an image sensor 300, allowing the circuit board 301 to move in directions perpendicular to the optical axis 201. Further, two relative displacement sensors 500, 501 and a positional movement detector 503 are used to send the displacement of a lens assembly 203 consisting of a lens 200 and a lens holder 202 relative to the circuit board 301 in x-axis and y-axis directions to an anti-shake controller 504, so that the circuit board 301 is driven by a movement driving unit 502 based on the displacement to move correspondingly in directions perpendicular to the optical axis 201 to thereby avoid the image sensor 300 from producing blurred image due to shake while shooting a picture.
Japanese Patent Laid Open No. 2002-207148 teaches a concept of avoiding blurred image caused by shaking while shooting a picture. The inventor of the present invention combines the same concept with a modularized auto-focus mechanism to devise an anti-shake auto-focus modular structure to integrate the auto-focus function and the anti-shake function into one lens module to satisfy the demands for an advanced camera lens module.